Researchers think a key ally in thawing out icy, barren wastelands of Mars is glitter—more specifically, literally millions of tons of reflective metallic nanorod particles seeded throughout the Red Planet’s atmosphere. But if that sounds like a huge order, the team calculates their proposal is potentially 5,000 times more efficient than previous ideas.
For some people, the ultimate goal of traveling to Mars isn’t to simply visit, or even plan extended stays in delicate temporary habitats—the dream is to terraform it into humanity’s Earthlike second home. Scientists and science fiction writers over the years have offered countless theories on how to start transforming the cold, lifeless world into a livable place. In 1971, Carl Sagan suggested vaporizing the northern polar ice caps, while Harvard researchers argued in 2017 that large amounts of silica aerogel could trap enough heat to regionally instigate greenhouse warming conditions. Elon Musk, meanwhile, has offered to nuke portions of Mars to initiate similar scenarios. Now, however, experts are suggesting a somewhat less aggressive first step: seeding the atmosphere of Mars with glittery nanorod particles.
[Related: What it was like to spend a year in NASA’s Mars base simulation.]
The plan was published August 7 in Science Advances, and comes from a collaboration between geophysicists at the University of Chicago, Northwestern University, and the University of Central Florida. Based on their calculations, Mars’ iron- and aluminum-rich surface dust may provide a great source material for manufacturing roughly 9-micrometer-long reflective nanorods. Massive amounts of these particles, each roughly the size of commercially available glitter, could trap any existing heat while scattering sunlight across the Martian surface to boost the planet’s natural greenhouse effect. According to their estimates, releasing stores of nanorods into the atmosphere at a rate of 30 liters-per-second would begin noticeably warming Mars within a matter of months, and eventually raise temperatures over 50-degrees Fahrenheit. The team also argues that more efficient nanoparticle designs in the future may even allow for higher temperature shifts.
“How light interacts with sub-wavelength objects is fascinating. Importantly, engineering nanoparticles can lead to optical effects that far exceed what is conventionally expected from such small particles,” Samaneh Ansari, a Northwestern University graduate student and study lead author, explained in a statement on Wednesday.
Ansari and their colleagues stress that although heating an entire planet by 50 degrees is dramatic by most standards, when it comes to Mars, it’s only the first of many steps needed to terraform Earth’s neighbor. Given that average temperatures on Mars are currently around -80 degrees Fahrenheit, the nanorod approach still wouldn’t be enough to make breathable conditions suitable for humans.
Of course, there are still many unknowns to the nanorod seeding scenario. Although the particles would certainly cycle out of the atmosphere over time, it’s not clear exactly how long it would take. And as Mars warms, it is possible that cloud vapor could begin condensing around the engineered “glitter” to return to the surface as metal-laden rain—possibly posing a health hazard to both humans and any necessary agriculture.
That said, -30 degrees Fahrenheit is sufficient to begin supporting microbial life and possibly even allow the cultivation of certain food crops—both necessary hurdles to clear on the way to a livable Mars. What’s more, the team thinks the nanorod warming method is reversible if necessary, as the particles cycle out of the atmosphere over a few years’ time.
[Related: Elon Musk’s Martian dreams include modded Cybertrucks and bioengineered animals.]
“Climate feedbacks are really difficult to model accurately,” Edwin Kite, a University of Chicago geophysical sciences professor and corresponding author, warned in the study’s announcement. “To implement something like this, we would need more data from both Mars and Earth, and we’d need to proceed slowly and reversibly to ensure the effects work as intended.”
In all likelihood, the window for terraforming Mars is realistically decades away—but if it does ever begin, it could do so with a glittery opening ceremony.
